Aircraft: CRJ900
Phase of flight: Initial Approach
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown

Shortly after contacting Tower on approach we were informed that runway lights at the airport were not coming on and the Tower was unable to reset. The Captain decided to continue the landing. At that time I informed the Captain that I believed that it was not legal to land without operating runway lights at night (I was about 95% sure). The Captain said that she would take full responsibility for the landing and would file an ASAP report if needed. She did inform me that either one of us could call the abort if we could not find the runway. She asked me to inform the Tower that we would continue with the landing. Tower told us to proceed at our own risk. A few seconds later Tower asked us if they should increase the intensity of the taxiway lights. We said yes. At this point I could see the airport complex. I was not able to see the runway except for a black rectangle devoid of any lights. I was about to call for a go around when the Captain said she had the runway in sight. We landed without any further incident after which the Captain said that she had very good night vision. I should have been more assertive and insisted that we not continue the approach. Had I been in command I would have aborted the landing and gone into a hold when the Tower informed us about the runway lights not working especially given the fact we had sufficient fuel. That would have given us enough time to let the Tower work on the lighting issue and for us to verify the FAR's/FOM. The reason I did not assert myself further was two fold. I was not 100% sure of the illegality of the landing and I was worried about the Captains reaction had I forced the issue and turned out to be wrong. There had already been a few instances during the short flight that the Captain had overruled my decisions on some minor instances in which I knew I was correct. Thus I assumed I would have been overruled. We were on final approach; we had declared the airport in sight and had been cleared for a visual approach. After transferring to Tower frequency (same Controller as approach frequency) and being cleared to land; the Controller stated that the runway lights would not illuminate. We had the PAPI lights in sight as well as taxiway lighting; we were on the ILS glide path. The Controller asked us to state our intentions for this arrival. I told the First Officer that I was comfortable landing on the runway. I also stated 'If you in any way feel uncomfortable with this approach at any time; we will go around and make an alternate decision. Are you okay with continuing?' He said he was okay to continue. I had him tell the Controller that we were okay to continue. The controller stated that he had contacted the county; but wasn't sure how long it would take them to fix the lighting. The Controller asked if we would like the taxiway lights turned brighter. We said 'sure; it won't hurt.' We continued the approach. I called the runway and runway markings in sight when I saw them. We landed smoothly and exited the runway. All conditions were achieved normally. The controller had us taxi to the gate. CRJ-900 flight crew is informed during a night visual approach that the runway lights will not come on. The Captain elects to continue; the First Officer is not so sure; but agrees and a normal landing ensues.